Valuable hydrocarbons by destructive hydrogenation



Jung 19, 1934. M. PIER 51" AL 1,963,759

VALUABLE HYDROCARBONS BY DESTRUCTIVE HYDRdGENATIoN Filed m. 21, 1931mVEN'roRs MfiTHIA PIER HURT m SEL.

ATTORNEY6 no y- Milne to colloidal su Patented June 19, 1934 VALUABLEwlgshai'en-on-theto Standard-I. G. Comp poration of DelawareApplicatioirn January 21,

HYDROGARBONS BY DESTRUC- TIVE HYDROGENATION Mathias Pier, Heidelberg,Rhine,

and Kurt Wissel, Lud- Germany, assignors any, Linden, N. J., a cor-1931, Serial No. 510,270

Germany January 24, 1930 4 Claims. (01. 196-53) j'I'his inventionrelates to improvements in the manufacture and production of valuablehydrocarbons from coal suspensions, tars, mineral oils,

the like by destructive hydrogenation.

A process has already been proposed for the marfufacture and productionof valuable hydrocarbons from carbonaceous materials in the liquid Iorlj'suspended or pasty condition, such as oraloil suspensions, tars,mineral oils and the like treatment in the liquid phase with hydrogenorfgases containing hydrogen at elevated temperatiires and increasedpressures of more than atmospheres, if desired in the presence ofcatalysts. In the said process such an intensive state 5' of movementmay be imparted to the material under treatmentin all those parts of theapparatus, where it is subjected to heat treatment, that no injuriouslocal thickening occurs, by vigorously stirring the said material bymechanical 2 means so that a thorough intermixing of the materialsessentially in upward-downward direction occurs and the hydrogenatinggas may be simultaneously introduced into the body of liquid from a gaspipe by means bringing the gas into division or into the form of finejets, thus ensuring a good distribution of the hydrogenating gas in theproduct under treatment, the participants in the reaction beingpreferably admitted and removed in acontinuous tov manner. The movementmay be affected invarious ways as for example by leading the proddots tobe treated in the hot state in a cycle while stirring them or by leadingthem with a higher linear velocity through the reaction zone or with aidof dredgers, scrapers, shovels and the like, the movement being carriedout in such a manner that a thorough mixing of the reaction materials iseifected. In this manner when employing catalysts, as for example in theform of spensions, these are always uniformly distributed in the li d inthe reaction chamber. A modification 0 thisprocess has been describedaccording to which instead of or in addition to the said means formaintaining as the suspension of the catalysts, other means are employedwhich consists in reducing the difference in the specific gravities ofthe material to be treated and the catalyst to such an extent that auniform distribution of the catalyst is always so; obtained.

. We have now found that the settling of the discatalyst'present in theliquid initial ma-. 'terials comprising an asphaltic substance to betreated may be prevented by precluding the simultaneous presence in thereaction mixture of ample para low boiling consti their employment'hydrogenating gas so th hydrocarbons rich in hydrogen, and inparticular of hydrocarbons of the said nature, which have a highmolecular weight. As a general rule the said hydrocarbons have amolecular weight of more than 250 and contain more than 10 or 11 percent of hydrogen. Thus in the treatment of liquid products containingasphaltic substances which expression, where herein employed includesresinous substances, and which contain a solid catalyst in a state ofdispersion, the settling of the catalyst is prevented by taking carethat substances having a flocculating action, in particular productsrich in hydrogen as for ex-- flinic hydrocarbons are excluded and thatan enrichment insuch substances is precluded. In this case alsohydrocarbons rich in hydrogen of low molecular weight should beparticularly excluded. All the asphaltic substances of the characterdefined are flocculated by the hydrocarbons rich in hydrogen referredto. the flocculating action of the low molecular weight hydrocarbonsbeing stronger than that of the high molecular weight hydrocarbons, butthe latter having a pronounced flocculating action when present insuiilcient concentration. It has been found in the treatment ofsubstances of the said kind that an enrichment of the liquid in thereaction vessel with hydrocarbons rich in hydrogen effects aflocculation of the asphaltic and resinous substances which aredissolved at the working temperatures employed and a conglomeration ofthe iine particles of catalyst with the flocculated substances takesplace. The catalySt then collects at the bottom of the reaction vesselso that its activity is partially or wholly lost and clogging andincrustations may take place in the apparatus. In order to avoid this,the initial materials are freed according to their nature from tuentsrich in hydrogen before by vacuum distillation, or in cases when thesaid constituents are formed during the heating period, they are removedat a suitable place before their entry into .the reaction vessel.Furthermore, the low boiling products rich in hydrogen formed in thereaction vessel during the process, such as middle oils and benzines,are removed from the reaction vessel immediately after their formationby the choice of a corresponding linear velocity of flow of the tunityto act on the liquid present in the reaction vessel.

In this. way the enrichment of the reaction mixture in hydrocarbons richin hydrogen is preeluded because most of the high boiling hydroat, theyhave no opporgroup of the periodic system in a carbons are unsaturatedin nature and, while the removal of the low boiling hydrogen richhydrocarbons is accompanied by a removal of low boiling unsaturatedhydrocarbons, the concentration of hydrogen rich hydrocarbons in theentire reaction mixture decreases.

Care should also be taken that the high molecular substances, such asparaffin hydrocarbons, which are present in the initial materials orwhich are formed during the hydrogenation, and which likewise effect aflocculation of the catalyst, are excluded to a large extent. In thiscase it is preferable to withdraw a part of the liquid material to betreated periodically or continuouslyfrom the reaction chamber, to removethe high molecular constituents rich in hydrogen,

'as for example by freeing from paraflins by cooling and subsequentcentrifuging, and to return the remainder to the reaction chamber. Inthis manner the concentration of high molecular products rich inhydrogen in the reaction liquid is kept very small so that the catalystremains suspended. Y

Again when working up high molecular products rich in hydrogen, such asparafiins or bituminous substances, the hydrocarbons containingasphaltic substances, such as mineral coal tar products, must beexcluded in the same way because in this case they also have afiocculating effect on the suspension of the catalyst.

All those catalysts usually employed in destructive hydrogenationprocesses, which are immunefrom poisoning by sulphur, and inparticularsuch comprising a metal of the sixth free or combined state such asmolybdenum, tungsten or chromium may be employed.

The process is pressures exceeding preferably carried out under 20atmospheres, and preferably at high pressures exceeding 50 atmospheres,as for example at 100, 200, 500, 800, 1000 atmospheres or even more.Temperatures of between 300 and 700 C. are usually employed,

' but usually temperatures of between 380 and hydrogen can be pumped bypump be described with reference One method for carrying out theinvention will to the accompanying drawing, but the invention is notrestricted to this particular method or the particular arrangementshown.

Crude oil containing asphaltic substances and hydrogen rich hydrocarbonsof high molecular weight, particularly parafiin wax, is led fromcontainer 30 into a centrifuge 31 into which is also introduced acooling liquid from tank 32. After being freed by-filtration from theheavy paraflins which were precipitated by the cooling liquid, the oilis fd to storage tank 1. By means of pump 2 the initial material can bepassed through line 3 and coil 4 which is placed in the preheater 5.Pipe 6 connects coil 4 with the high pressure reaction vessel 7. 8 is apipe for leading the products from vessel 7 to the separator 9 fromwhich liquid products can either be withdrawn through line 10 for anypurpose or from which the said liquid products can be returned by meansof pump 11 through line 12 to coil 4. Fresh 13 through line 14 toheating coil 15 arranged in the preheater 5. Coil 15 is connected bypipe 16 with the device 17 for spraying the hydrogen into the materialin the reaction vessel '7. The above mentioned separator 9 is connectedby means of pipe 18 with the cooler 19. The portions liquefied in 19 areseparated in the separator 20 from which is hydrogenated under mill 26is suitable for mixing the catalyst with a suitable oil poor inhydrogen, preferably a part of the product to be treated. By means ofpump 27 the mixture can be forced through line 28 .into the reactionvessel 7.

The following examples will further illustrate the nature of thisinvention, but the invention is not restricted to these examples. Theparts are by weight.

Example 1 Referring to the accompanying drawing, a brown coal lowtemperature carbonization tar is completely freed from paraffin wax bycooling in stages and filtering and stored in tank 1 after distillingoff the constituents boiling below 325 C.: The stored product containsabout 15 per centof asphalt. It is pumpedby pump 2 throughline 3 intothe coil 4,'arranged in preheater 5,-where it is preheated to aboutreaction temp'erature. Recovered hydrogenating gas mixedwithjhe' productbefore coil-4. The heated mixture passes, through line 6 into vessel '7.Here the'inatejrial, 200 atmospheres at 450 C. in the liquid phase. Acatalyst consistinglofl molybdic acid and zinc oxide which has been col;loidally ground in mill and mixedwith apart of the product to be treatedin mill'26 is-;added.- to the contents of the reaction vessel. The tureis pumped by means ofpump 27. through line 28 into vessel 7. The productto beQtreated, contains about 20 per cent of catalyst. The hot: reactionproducts pass through pipe 3 to the sepa; rator 9. Part of the liquidproducts separated therein can be withdrawn through line 10.. Pref-ferably, however, it is pumped by'pump 11 back to, the preheated coil 4.By circulating the hot 00s,; tents of the reaction vessel by pumping}.such velocity of flow is maintained that no sedimenta tion of thesuspended catalyst or the high molecu-.- lar asphalt takes place.Furthermore, about 4. cubic metres of hydrogen to. each kilogram; of-nilmust be introduced so that the reaction=products rich in hydrogen arecontinuously rerii'ovedandQ haveno opportunityto exert a flocculatingac-..

tion on the liquid containing asphalt in the .high-, pressure vesselbyreasonof its remainingthere in for long periods of time. This isefiectedby introducing fresh hydrogen bypump 1 3 through line 14, coil15, line 16 and spraying. device 1'? and by recycling hydrogenatinggaspurified, in; 23 through line 24. The vaporous products leaving thevessel 9 together with the hydrogen contain 15 per cent of motor benzineand 80 per cent of middle oil boiling up to 325 .0. As far as theseliquid products are not removed in sepaf rator 9., they pass throughpipe 18, are cooled in} cooler 19, separated in 20 and withdrawn tfflughi 21.: The fixed gasespass through line 22 were" gas purificationdevice 23.

Example from molybdic acid, chromic acid and 1116118811159 nesecarbonate. The catalyst is maintained in a state of fine distributionina concentration of from 15 to 20 per cent in the liquid situated inthe high pressure vessel by continuously circulating the same. A productis obtained which consists of 25 per cent of non-knocking motor benzineand '75 per cent of middle oil.

What we claim is:-

1. In the destructive hydrogenation of a liquid carbonaceous materialcomprising paraflinic hydrocarbons and asphaltic substances andcontaining a solid catalyst immune to sulphur poisoning in a state ofsuspension, the steps of preventing the settling of the catalyst byflocculation of the asphaltic substances by adjusting the concentrationof the parafiinic hydrocarbons in the initial material to a point wherethey will not cause flocculation of asphalt by removal of any paraffinsin excess of this concentration before introduction of the initialmaterial into the reaction vessel and'preventing an increase in theconcentration of parainnic hydrocarbons in the reaction vessel byremoving low boiling paraflins as soon as formed and, in the event thatthe concentration of high boiling parafiins becomes too great, removinga portion of the reaction mixture, separating the parafiins therefromand returning the paraflin free material to the reaction vessel.

2. In the destructive hydrogenation of a liquid carbonaceous materialcomprising paraflinic hydrocarbons and asphaltic substances andcontaining a solid catalyst immune t; sulphur poisoning in a state ofsuspension, the steps of preventing the settling of the catalyst byflocculation of the asphaltic substances by adjusting the concentrationof the paraiifinic hydrocarbons in the initial material to a point wherethey will not cause flocculation of asphalt by removal of any paraffinsin excess of this concentration before introduction of the initialmaterial into the reaction vessel and preventing an increase in theconcentration of paraffinic hydrocarbons in the reaction vessel byremoving low boiling parafiins as soon as formed by employing a highrate of flow of the hydrogenating gas and, in the event that theconcentrationof high boiling paraflins becomes too great, removing aportion of the reaction mixture, separating the paraflins therefrom andreturning the paraflin free material to the reaction vessel.

3. In the destructive hydrogenation of a liquid carbonaceous materialcomprising paraflinic hydrocarbons of high molecular weight and as-.phaltic substances and containing a solid catalyst immune to sulphurpoisoning in a state of suspension, the steps of preventing the settlingof the catalyst by flocculation of the asphaltic substances by adjustingthe concentration of the heavy paraffinic hydrocarbons in-the initialmaterial to a point where they will not cause flocculation of asphalt bya removal of any heavy parafiins in excess of this concentration beforeintroduction of the initial material into the reaction vessel andpreventing an increase in the concentration of parafunic hydrocarbons inthe reaction vessel by removing low boiling paraffins as soon as formedand, in the event that the concentration. of high boiling paraflinsbecomes too great, removing a portion of the reaction mixture,separating the paraflins therefrom and returning the paraflin freematerial to the reaction vessel.

4. In the destructive hydrogenation of brown coal low temperature 'tarrich in asphaltic substances and containing paraflin wax, the steps ofreducing the concentration of the paraflin wax in the initial materialbelow the'point at which it can cause flocculation of the asphalticsubstances contained therein by cooling the tar and filterin adding acolloidally ground catalyst comprising molybdic acid and zinc oxide tothe residual tar, and destructively hydrogenating the mixture thusobtained with a strong stream of hydrogen under a pressure of about 200atmospheres and at a temperature of about 450 C., whereby any lowboiling paraflinic hydrocarbons are immediately removed from thereaction vessel, and maintaining the reaction materials in a vigorousstate of motion whereby settling of the catalyst is prevented.

MATI-HAS PIER. KURT WISSEL.

